/* vi: set sw=4 ts=4: */ /* * Russ Dill September 2001 * Rewritten by Vladimir Oleynik (C) 2003 * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ #ifndef UDHCP_COMMON_H #define UDHCP_COMMON_H 1 #include "libbb.h" #include "common_bufsiz.h" #include #include PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN extern const uint8_t MAC_BCAST_ADDR[6] ALIGN2; /* six all-ones */ /*** DHCP packet ***/ #define RFC1048_MAGIC 0x63825363 /* RFC 1048 still uses BOOTP's small buffer (4 byte cookie + 60 the rest) */ #define RFC1048_OPTIONS_BUFSIZE 60 /* DHCP protocol. See RFC 2131 */ #define DHCP_OPTIONS_BUFSIZE 308 #define BOOTREQUEST 1 #define BOOTREPLY 2 //TODO: rename ciaddr/yiaddr/chaddr struct dhcp_packet { uint8_t op; /* BOOTREQUEST or BOOTREPLY */ uint8_t htype; /* hardware address type. 1 = 10mb ethernet */ uint8_t hlen; /* hardware address length */ uint8_t hops; /* used by relay agents only */ uint32_t xid; /* unique id */ uint16_t secs; /* elapsed since client began acquisition/renewal */ uint16_t flags; /* only one flag so far: */ #define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */ uint32_t ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */ uint32_t yiaddr; /* 'your' (client) IP address */ /* IP address of "next server" (usually meant to be an TFTP server) * to use in bootstrap, returned in DHCPOFFER, DHCPACK by server: */ uint32_t siaddr_nip; /* RFC 951 (BOOTP): "place my (server) IP address in the 'siaddr' field" * (IOW: unconditionally, not just if we are also a TFTP server). * DHCP servers don't have to do this, they add SERVER_ID option * to their reply packets to let client identify lease-giving server. */ uint32_t gateway_nip; /* aka 'giaddr': relay agent IP address, else 0 */ uint8_t chaddr[16]; /* link-layer client hardware address (MAC) */ uint8_t sname[64]; /* server host name (ASCIZ) */ /* RFC 951 (BOOTP): "If the client wishes to restrict booting * to a particular server name, it may place [it] in 'sname'" */ uint8_t file[128]; /* boot file name (ASCIZ) */ /* RFC 951 (BOOTP): in client requests, "...can be a 'generic' name * such as 'unix' or 'gateway'; this means 'boot the named program * configured for my machine'" */ /* BOOTP fields end here, BOOTP says optional uint8_t vend[64] follows. */ /* RFC 1048 defined this cookie value and options 0-12 and 255. */ /* DHCP extended it and required option 255 (END) to be always present. */ uint32_t cookie; /* RFC 1048 magic bytes: 99,130,83,99 decimal */ uint8_t options[DHCP_OPTIONS_BUFSIZE + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS]; }; #define DHCP_PKT_SNAME_LEN 64 #define DHCP_PKT_FILE_LEN 128 #define DHCP_PKT_SNAME_LEN_STR "64" #define DHCP_PKT_FILE_LEN_STR "128" struct ip_udp_dhcp_packet { struct iphdr ip; struct udphdr udp; struct dhcp_packet data; }; struct udp_dhcp_packet { struct udphdr udp; struct dhcp_packet data; }; enum { IP_UDP_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, UDP_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, DHCP_SIZE = sizeof(struct dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, }; /* Let's see whether compiler understood us right */ struct BUG_bad_sizeof_struct_ip_udp_dhcp_packet { char c[IP_UDP_DHCP_SIZE == 576 ? 1 : -1]; }; /*** Options ***/ enum { OPTION_IP = 0, OPTION_IP_PAIR, OPTION_STRING, /* Opts of STRING_HOST type will be sanitized before they are passed * to udhcpc script's environment: */ OPTION_STRING_HOST, // OPTION_BOOLEAN, OPTION_U8, OPTION_U16, // OPTION_S16, OPTION_U32, OPTION_S32, OPTION_BIN, OPTION_STATIC_ROUTES, OPTION_6RD, #if ENABLE_FEATURE_UDHCP_RFC3397 || ENABLE_FEATURE_UDHCPC6_RFC3646 || ENABLE_FEATURE_UDHCPC6_RFC4704 OPTION_DNS_STRING, /* RFC1035 compressed domain name list */ #endif #if ENABLE_FEATURE_UDHCP_RFC3397 OPTION_SIP_SERVERS, #endif OPTION_TYPE_MASK = 0x0f, /* Client requests this option by default */ OPTION_REQ = 0x10, /* There can be a list of 1 or more of these */ OPTION_LIST = 0x20, }; struct dhcp_scan_state { int overload; int rem; uint8_t *optionptr; }; /* DHCP option codes (partial list). See RFC 2132 and * http://www.iana.org/assignments/bootp-dhcp-parameters/ * Commented out options are handled by common option machinery, * uncommented ones have special cases (grep for them to see). */ #define DHCP_PADDING 0x00 #define DHCP_SUBNET 0x01 //#define DHCP_TIME_OFFSET 0x02 /* (localtime - UTC_time) in seconds. signed */ //#define DHCP_ROUTER 0x03 //#define DHCP_TIME_SERVER 0x04 /* RFC 868 time server (32-bit, 0 = 1.1.1900) */ //#define DHCP_NAME_SERVER 0x05 /* IEN 116 _really_ ancient kind of NS */ //#define DHCP_DNS_SERVER 0x06 //#define DHCP_LOG_SERVER 0x07 /* port 704 UDP log (not syslog) */ //#define DHCP_COOKIE_SERVER 0x08 /* "quote of the day" server */ //#define DHCP_LPR_SERVER 0x09 #define DHCP_HOST_NAME 0x0c /* 12: either client informs server or server gives name to client */ //#define DHCP_BOOT_SIZE 0x0d //#define DHCP_DOMAIN_NAME 0x0f /* 15: server gives domain suffix */ //#define DHCP_SWAP_SERVER 0x10 //#define DHCP_ROOT_PATH 0x11 //#define DHCP_IP_TTL 0x17 //#define DHCP_MTU 0x1a //#define DHCP_BROADCAST 0x1c //#define DHCP_ROUTES 0x21 //#define DHCP_NIS_DOMAIN 0x28 //#define DHCP_NIS_SERVER 0x29 //#define DHCP_NTP_SERVER 0x2a //#define DHCP_WINS_SERVER 0x2c #define DHCP_REQUESTED_IP 0x32 /* 50: sent by client if specific IP is wanted */ #define DHCP_LEASE_TIME 0x33 /* 51: 32bit big-endian */ #define DHCP_OPTION_OVERLOAD 0x34 /* 52: 1 byte */ #define DHCP_MESSAGE_TYPE 0x35 /* 53: 1 byte */ #define DHCP_SERVER_ID 0x36 /* 54: server's IP */ #define DHCP_PARAM_REQ 0x37 /* 55: list of options client wants */ //#define DHCP_ERR_MESSAGE 0x38 /* 56: error message when sending NAK etc */ #define DHCP_MAX_SIZE 0x39 /* 57: 16bit big-endian */ // 0x3a /* 58: from server: renew time, 32bit big-endian */ // 0x3b /* 59: from server: rebind time, 32bit big-endian */ #define DHCP_VENDOR 0x3c /* 60: client's vendor (a string) */ #define DHCP_CLIENT_ID 0x3d /* 61: by default client's MAC addr, but may be arbitrarily long */ //#define DHCP_TFTP_SERVER_NAME 0x42 /* 66: same as 'sname' field */ //#define DHCP_BOOT_FILE 0x43 /* 67: same as 'file' field */ //#define DHCP_USER_CLASS 0x4d /* 77: RFC 3004. set of LASCII strings. "I am a printer" etc */ // 0x50 /* 80: rapid commit ("I'm ok with getting immediate ACK, not just OFFER"), 0 bytes */ #define DHCP_FQDN 0x51 /* 81: client asks to update DNS to map its FQDN to its new IP */ //#define DHCP_PCODE 0x64 /* 100: RFC 4833. IEEE 1003.1 TZ string */ //#define DHCP_TCODE 0x65 /* 101: RFC 4833. Reference to the TZ database string */ //#define DHCP_DOMAIN_SEARCH 0x77 /* 119: RFC 3397. set of ASCIZ string, DNS-style compressed */ //#define DHCP_SIP_SERVERS 0x78 /* 120: RFC 3361. flag byte, then: 0: domain names, 1: IP addrs */ //#define DHCP_STATIC_ROUTES 0x79 /* 121: RFC 3442. (mask,ip,router) tuples */ //#define DHCP_VLAN_ID 0x84 /* 132: 802.1P VLAN ID */ //#define DHCP_VLAN_PRIORITY 0x85 /* 133: 802.1Q VLAN priority */ //#define DHCP_PXE_CONF_FILE 0xd1 /* 209: RFC 5071 Configuration file */ //#define DHCP_PXE_PATH_PREFIX 0xd2 /* 210: RFC 5071 Path prefix */ //#define DHCP_REBOOT_TIME 0xd3 /* 211: RFC 5071 Reboot time */ //#define DHCP_MS_STATIC_ROUTES 0xf9 /* 249: Microsoft's pre-RFC 3442 code for 0x79? */ //#define DHCP_WPAD 0xfc /* 252: MSIE's Web Proxy Autodiscovery Protocol */ #define DHCP_END 0xff /* 255: */ /* Offsets in option byte sequence */ #define OPT_CODE 0 #define OPT_LEN 1 #define OPT_DATA 2 /* Offsets in option byte sequence for DHCPv6 */ #define D6_OPT_CODE 0 #define D6_OPT_LEN 2 #define D6_OPT_DATA 4 /* Bits in "overload" option */ #define OPTION_FIELD 0 #define FILE_FIELD 1 #define SNAME_FIELD 2 /* DHCP_MESSAGE_TYPE values */ #if ENABLE_FEATURE_UDHCPD_BOOTP #define MSGTYPE_BOOTP 0 /* there was no TYPE option in client's packet, assuming BOOTP */ #endif #define DHCPDISCOVER 1 /* client -> server */ #define DHCPOFFER 2 /* client <- server */ #define DHCPREQUEST 3 /* client -> server */ #define DHCPDECLINE 4 /* client -> server */ #define DHCPACK 5 /* client <- server */ #define DHCPNAK 6 /* client <- server */ #define DHCPRELEASE 7 /* client -> server */ #define DHCPINFORM 8 /* client -> server */ #define DHCP_MINTYPE DHCPDISCOVER #define DHCP_MAXTYPE DHCPINFORM struct dhcp_optflag { uint8_t flags; uint8_t code; }; struct option_set { uint8_t *data; struct option_set *next; }; #if ENABLE_UDHCPC || ENABLE_UDHCPD extern const struct dhcp_optflag dhcp_optflags[]; extern const char dhcp_option_strings[] ALIGN1; #endif extern const uint8_t dhcp_option_lengths[] ALIGN1; unsigned FAST_FUNC udhcp_option_idx(const char *name, const char *option_strings); void init_scan_state(struct dhcp_packet *packet, struct dhcp_scan_state *scan_state) FAST_FUNC; uint8_t *udhcp_scan_options(struct dhcp_packet *packet, struct dhcp_scan_state *scan_state) FAST_FUNC; uint8_t *udhcp_get_option(struct dhcp_packet *packet, int code) FAST_FUNC; /* Same as above + ensures that option length is 4 bytes * (returns NULL if size is different) */ uint8_t *udhcp_get_option32(struct dhcp_packet *packet, int code) FAST_FUNC; int udhcp_end_option(uint8_t *optionptr) FAST_FUNC; void udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt) FAST_FUNC; #if ENABLE_UDHCPC || ENABLE_UDHCPD void udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data) FAST_FUNC; #endif #if ENABLE_FEATURE_UDHCP_RFC3397 || ENABLE_FEATURE_UDHCPC6_RFC3646 || ENABLE_FEATURE_UDHCPC6_RFC4704 char *dname_dec(const uint8_t *cstr, int clen, const char *pre) FAST_FUNC; uint8_t *dname_enc(/*const uint8_t *cstr, int clen,*/ const char *src, int *retlen) FAST_FUNC; #endif #if !ENABLE_UDHCPC6 #define udhcp_find_option(opt_list, code, dhcpv6) \ udhcp_find_option(opt_list, code) #endif struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code, bool dhcpv6) FAST_FUNC; // RFC 2131 Table 5: Fields and options used by DHCP clients // // Fields 'hops', 'yiaddr', 'siaddr', 'giaddr' are always zero, 'chaddr' is always client's MAC // // Field DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE // ----- ------------ ------------ ----------- ----------- ----------- // 'xid' selected by client selected by client 'xid' from server selected by client selected by client // DHCPOFFER message // 'secs' 0 or seconds since 0 or seconds since 0 or seconds since 0 0 // DHCP process started DHCP process started DHCP process started // 'flags' Set 'BROADCAST' Set 'BROADCAST' Set 'BROADCAST' 0 0 // flag if client needs flag if client needs flag if client needs // broadcast reply broadcast reply broadcast reply // 'ciaddr' 0 client's IP 0 or client's IP 0 client's IP // (BOUND/RENEW/REBIND) // 'sname' options or sname options or sname options or sname (unused) (unused) // 'file' options or file options or file options or file (unused) (unused) // 'options' options options options message type opt message type opt // // Option DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE // ------ ------------ ---------- ----------- ----------- ----------- // Requested IP address MAY MUST NOT MUST (in SELECTING MUST MUST NOT // or INIT-REBOOT) // MUST NOT (in BOUND // or RENEWING) // IP address lease time MAY MUST NOT MAY MUST NOT MUST NOT // Use 'file'/'sname' fields MAY MAY MAY MAY MAY // Client identifier MAY MAY MAY MAY MAY // Vendor class identifier MAY MAY MAY MUST NOT MUST NOT // Server identifier MUST NOT MUST NOT MUST (after SELECTING) MUST MUST // MUST NOT (after // INIT-REBOOT, BOUND, // RENEWING or REBINDING) // Parameter request list MAY MAY MAY MUST NOT MUST NOT // Maximum message size MAY MAY MAY MUST NOT MUST NOT // Message SHOULD NOT SHOULD NOT SHOULD NOT SHOULD SHOULD // Site-specific MAY MAY MAY MUST NOT MUST NOT // All others MAY MAY MAY MUST NOT MUST NOT /*** Logging ***/ #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1 # define IF_UDHCP_VERBOSE(...) __VA_ARGS__ extern unsigned dhcp_verbose; # define log1(...) do { if (dhcp_verbose >= 1) bb_info_msg(__VA_ARGS__); } while (0) //# define log1s(msg) do { if (dhcp_verbose >= 1) bb_simple_info_msg(msg); } while (0) void log1s(const char *msg) FAST_FUNC; # if CONFIG_UDHCP_DEBUG >= 2 void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC; # define log2(...) do { if (dhcp_verbose >= 2) bb_info_msg(__VA_ARGS__); } while (0) # define log2s(msg) do { if (dhcp_verbose >= 2) bb_simple_info_msg(msg); } while (0) # else # define udhcp_dump_packet(...) ((void)0) # define log2(...) ((void)0) # define log2s(msg) ((void)0) # endif # if CONFIG_UDHCP_DEBUG >= 3 # define log3(...) do { if (dhcp_verbose >= 3) bb_info_msg(__VA_ARGS__); } while (0) # define log3s(msg) do { if (dhcp_verbose >= 3) bb_simple_info_msg(msg); } while (0) # else # define log3(...) ((void)0) # define log3s(msg) ((void)0) # endif #else # define IF_UDHCP_VERBOSE(...) # define udhcp_dump_packet(...) ((void)0) # define log1(...) ((void)0) # define log1s(msg) ((void)0) # define log2(...) ((void)0) # define log2s(msg) ((void)0) # define log3(...) ((void)0) # define log3s(msg) ((void)0) #endif /*** Other shared functions ***/ /* 2nd param is "uint32_t*" */ int FAST_FUNC udhcp_str2nip(const char *str, void *arg); #if !ENABLE_UDHCPC6 #define udhcp_insert_new_option(opt_list, code, length, dhcpv6) \ udhcp_insert_new_option(opt_list, code, length) #endif void* FAST_FUNC udhcp_insert_new_option(struct option_set **opt_list, unsigned code, unsigned length, bool dhcpv6); /* 2nd param is "struct option_set**" */ #if !ENABLE_UDHCPC6 #define udhcp_str2optset(str, arg, optflags, option_strings, dhcpv6) \ udhcp_str2optset(str, arg, optflags, option_strings) #endif int FAST_FUNC udhcp_str2optset(const char *str, void *arg, const struct dhcp_optflag *optflags, const char *option_strings, bool dhcpv6); #if ENABLE_UDHCPC || ENABLE_UDHCPD void udhcp_init_header(struct dhcp_packet *packet, char type) FAST_FUNC; #endif int udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) FAST_FUNC; int udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, uint32_t source_nip, int source_port, uint32_t dest_nip, int dest_port, const uint8_t *dest_arp, int ifindex) FAST_FUNC; int udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt, uint32_t source_nip, int source_port, uint32_t dest_nip, int dest_port, const char *ifname) FAST_FUNC; void udhcp_sp_setup(void) FAST_FUNC; void udhcp_sp_fd_set(struct pollfd *pfds, int extra_fd) FAST_FUNC; int udhcp_sp_read(void) FAST_FUNC; int udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) FAST_FUNC; int udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) FAST_FUNC; /* Returns 1 if no reply received */ int arpping(uint32_t test_nip, const uint8_t *safe_mac, uint32_t from_ip, uint8_t *from_mac, const char *interface, unsigned timeo) FAST_FUNC; /* note: ip is a pointer to an IPv6 in network order, possibly misaliged */ int sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip) FAST_FUNC; POP_SAVED_FUNCTION_VISIBILITY #endif